MiR-25 Protects Cardiomyocytes against Oxidative Damage by Targeting the Mitochondrial Calcium Uniporter

Autor: Lei Pan, Bi-Jun Huang, Xiu-E Ma, Shi-Yi Wang, Jing Feng, Fei Lv, Yuan Liu, Yi Liu, Chang-Ming Li, Dan-Dan Liang, Jun Li, Liang Xu, Yi-Han Chen
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: International Journal of Molecular Sciences, Vol 16, Iss 3, Pp 5420-5433 (2015)
Druh dokumentu: article
ISSN: 1422-0067
DOI: 10.3390/ijms16035420
Popis: MicroRNAs (miRNAs) are a class of small non-coding RNAs, whose expression levels vary in different cell types and tissues. Emerging evidence indicates that tissue-specific and -enriched miRNAs are closely associated with cellular development and stress responses in their tissues. MiR-25 has been documented to be abundant in cardiomyocytes, but its function in the heart remains unknown. Here, we report that miR-25 can protect cardiomyocytes against oxidative damage by down-regulating mitochondrial calcium uniporter (MCU). MiR-25 was markedly elevated in response to oxidative stimulation in cardiomyocytes. Further overexpression of miR-25 protected cardiomyocytes against oxidative damage by inactivating the mitochondrial apoptosis pathway. MCU was identified as a potential target of miR-25 by bioinformatical analysis. MCU mRNA level was reversely correlated with miR-25 under the exposure of H2O2, and MCU protein level was largely decreased by miR-25 overexpression. The luciferase reporter assay confirmed that miR-25 bound directly to the 3' untranslated region (UTR) of MCU mRNA. MiR-25 significantly decreased H2O2-induced elevation of mitochondrial Ca2+ concentration, which is likely to be the result of decreased activity of MCU. We conclude that miR-25 targets MCU to protect cardiomyocytes against oxidative damages. This finding provides novel insights into the involvement of miRNAs in oxidative stress in cardiomyocytes.
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